1. Field of the Invention
The present invention relates to an optical film comprising a cholesteric liquid crystal layer, and a method of producing the same.
2. Description of the Related Art
Cholesteric liquid crystals have properties of selectively reflecting specific circularly polarized light having a specific wavelength and transmitting other wavelengths and circularly polarized light and have been used for color filters or bright enhancement films of display devices.
Further, a technique of utilizing a cholesteric liquid crystal layer for an identification medium is also known (JP2015-116509A). JP2015-116509A suggests a simple and highly productive production method of forming a hologram layer, whose surface used for displaying holograms has an uneven shape, with a cholesteric liquid crystal compound.
Meanwhile, JP2008-268724A discloses an example of applying a cholesteric liquid crystal layer to a reflective diffraction polarizer. JP2008-268724A suggests a reflective diffraction polarizer having a birefringent film which is formed of a cholesteric liquid crystal layer and has an uneven diffraction grating structure.